In Collapse: How Societies Choose to Fail or Succeed, Jared Diamond claims that several societies in times past collapsed in part for environmental reasons and that these cases bear lessons for today. By and large, Diamond has got his history right. But the application of lessons derived from these historical cases to today's environmental problems will leave many readers unconvinced. Scaling up from diminutive, isolated, and low-technology examples such as precontact Easter Island or the Greenland Norse to the contemporary world is fraught with conceptual difficulties, not all of which Diamond can dispel. Diamond's arguments, whether one finds them convincing or not, raise some timely questions. Are we indeed at serious risk of environmental collapse? And how do some current trends—the rise of China, the coming transition to a new energy regime, and the slowing of population growth—affect the chances of environmental collapse?